1. Field of the Invention
The invention relates to a router table adapter base plate for affixing various router models and configurations to a router table.
2. Description of the Related Art
Electric routers are used to handle a wide variety of woodworking tasks. A typical router includes an electric motor mounted inside of a housing having handles by which the router may be held and manipulated manually. The motor shaft has a collet which accepts a tool (also called a router bit or cutter); a base is attached to the housing that surrounds the cutter such that a portion of the cutter protrudes from the base when the cutter is brought into contact with the work piece. The cutter rotates and removes a small volume of the work piece each time a cutter blade engages the work piece, which is achieved by applying force between the router cutter and work piece in the direction of a cut. The base may be adjusted in parallel to the rotating axis of the motor, and the relative position of the base and cutter can change while the tool is in use by xe2x80x9cplungingxe2x80x9d the tool into the work piece.
Although routers are often operated by keeping the work piece stationary and moving the router relative to the fixed work piece in a free-handed manner, the router may also be mounted in a table having a wide surface to work on in an inverted position, with the cutter projecting up from the table through an opening. With the router in this stationary operating position, the work piece may be moved relative to the fixed router thus permitting an accurate manipulation of the work piece.
Such work tables are known in the art. These work tables include some mechanism for mounting the router in a fixed position with sufficient rigidity to prevent the router from moving. This mechanism typically includes either holes drilled directly in the table in a position such that the router may be fastened to the table, or it includes a base plate to which the router is fastened, with the base plate then being attached to the work table.
An example of a base plate used in this manner can be found in U.S. Pat. No. 5,725,038 which illustrates attaching a router to a baseplate, with the assembly being fixed to a work table. In this arrangement, the router is suspended with the baseplate positioned within a hole in a router table top just slightly larger than the baseplate and resting on a lip or ledge below the top surface of the table top equal to the thickness of the baseplate.
One difficulty in utilizing routers in this manner with a work table is that there is no universal standard for mounting routers. Positions of attachment mechanisms tend to vary not only from manufacturer to manufacturer, but even within a given manufacturer, depending on the size or other characteristics of the router.
In order to accommodate different router configurations, various techniques have been employed. For example, according to the Craftsman Router Adapter Plate for Industrial Router Tables: Instructions for Assembly and Installation of Your Model No. 171.25333, January, 1997, a template having concentric circles of various sizes printed on it is attached to the router adapter plate using tape. The router is placed on the adapter plate with the template on, and the location of the base plate mounting holes are marked using a pencil or felt tipped marker. Holes are then drilled at the previously marked hole positions. The template is then removed, and the router is attached to the base plate with screws going through the holes that were previously drilled.
While this technique permits a base plate to accommodate any router that has been designed with attachment screws/holes, it involves a substantial amount of work on the part of the purchaser. First, it requires that the user have a drill with the correct size drill bits on hand. Second, it requires time and effort to properly drill the required holes. The positions must be properly and accurately markedxe2x80x94while using the template provided is a helpful aid, it is by no means foolproof. Erroneous hole locations could still potentially resultxe2x80x94these would be difficult if not impossible to correct. Also, the holes may be required to have a particular countersink to work properly. Purchasing the necessary tools to complete the job result in greater incurred expenses. Furthermore, this process would have to be repeated for each and every different router configuration that might be used.
In order to eliminate the step of users drilling the holes themselves, adapter plates have been created which can accommodate various router configurations. For example, the Craftsman Router Universal Adapter Plate for Assembly and Operationxe2x80x94Owner""s Manual for Model No. 171.25326 provides an adapter plate that is pre-drilled and slotted to accommodate a number of different routers. Although the holes and slots are pre-drilled in this adapter plate, however, various mechanism are utilized by it to minimize the number of holes and slots in the plate. The use of slots to accommodate router configurations of varying sizes does allow flexibility, but results in a mounting that is not as solid as one that exclusively used holes. There is a small degree of play in the router that results from the use of slotsxe2x80x94this results from the inherent strength and stiffness of the material from which the router plate is manufactured. Also, the additional material removed from the adapter plate to make slots, as opposed to holes, results in a weakened plate design over one that uses only holes, and is not as durable. Although the strength could be increased with other techniques such as using stronger material or making the plate thicker, these techniques would result in an increased material and production cost.
Furthermore, this design requires the use of additional countersink bushings in order to accommodate the various types of countersinks present on different router models. These countersink bushings increase the cost of an adapter plate over a design that doesn""t require them, and make the plate more difficult to install.
For these reasons, it is desirable to have a router adapter base plate that can be quickly connected to a router and provides a strong mounting for the router when the plate-router assembly is mounted on a table.
The invention is based on a strong slotless router adapter plate that can accommodate a large number of different routers and that minimizes the effort required by a user to attach to a router and minimizes cost.
This object is achieved by a slotless router base plate having pre-existing holes for a large majority of the routers presently on the market present in the router plate at the time of purchase. The inventive base plate has no fewer than six hole groupings, with each hole grouping having at least two holes. Since these holes are pre-existing at the time of purchase, there is no need for the purchaser to drill any holes themselves, make use of any templates, perform the proper countersinking/counterboring, or incur any additional costs associated with adapting a router plate to a particular model router. Furthermore, the inventive base plate requires no slots, which can result in a poorer mounting and structurally weaken the base plate.
The hole groupings in the inventive base plate were selected based on extensive market research to accommodate the vase majority of routers on the market today. Broadly, the invention identifies the selection of groups and holes required to accommodate various routing configurations, but narrowly in that the precise locations of the holes, as well as the sizes and shapes (i.e., counterboring, countersinking, adaption with an inset to accommodate a nut or other fastening device) are provided.
An additional embodiment provides for an identification of holes to the hole patterns to facilitate fastening the plate to a particular router model; these identifiers may be provided as a relief within the base plate itself for durability, but may also include surface etching, painting, or some other permanent way of providing identification for the holes.
Furthermore, the inventive base plate containing the hole pattern may be round, but is not limited to the round shape. Any other appropriate geometric shape may be used, or the inventive hole pattern may be created directly in a router table to hole a router.